The present invention provides an improvement in the packaging of hard disc drives for computer systems. Computer hard disc drives are often produced by manufacturers for sale to original equipment manufactures (OEMs) or for shipment to computer resellers. As is for most items, the physical characteristics of the item to be shipped play a significant role in the shipping costs that will be incurred. As such most manufacturers attempt to minimize the physical size, weight, and numerosity of items to be shipped.
Disc drives are generally shipped in large shipping containers containing multiple units, so as to minimize costs. In packaging these computer disc drives, care must be taken to prevent the drives from being damaged enroute. Specifically, the drives must be protected from shock and electro-static discharge (ESD).
Computer disc drives are known to be sensitive to ESD, necessitating the isolation of the disc drives from static generating sources. In the prior art, each individual disc drive was placed in a specially produced ESD resistant baggie with the appropriate warning labels affixed. The baggies represent a practical form of protection, providing a measure of isolation of the disc drive from external ESD sources. While this represents a safe method of shipping the devices, the individual wrapping time, and added space and weight to the shipment reduces the overall profitability of each device.
Additionally, in shipments to OEMs and computer vendors who are well versed in ESD protection, the individual wrapping causes more burden than protection. This is because the OEMs and computer vendors, along with original manufacturers, practice other better forms of protection such as utilizing grounding methods, static guards (leg-stats and wrist-stats), and humidity controlled environments in order to protect the devices. As such, the need for individual wrapping arises from the shipment alone. While baggies satisfy these shipping protection requirements, the industry ships voluminous amounts of ESD sensitive devices, and as such would benefit from any improvement in the protection methodologies presently known.
Similarly, the computer disc drives must be protected from the sometimes harsh shipping environments in order to assure product fidelity upon delivery. Shocks, in the form of drops and knocks are well known in the shipping industry at levels from 600 to 800 Gs for shipping containers. A measure of a packaging materials performance can be assessed by the materials ability to dissipate shock, and is often measured by performing shock tests. Shock tests simulate shipping environments. By a process of repeatedly dropping the packaged devices from heights up to 48 inches the performance of the packaging material can be measured. Because shock levels at or above 90 Gs represent those kinds of knocks and drops found to damage disc drives, performance is based on a packaging material's ability to repeatedly dissipate shocks to a level less than 90 Gs.
In the prior art, packaging material constructed from expanded polystyrene has been commonly employed to be utilized in the shipment of disc drives. Expanded polystyrene packaging has heretofore been desirable because of its light weight, low cost and molding characteristics which allow the production of molded cutouts to form fit to individual devices within a tolerance of .+-.1 mm. However, expanded polystyrene packaging materials tend to shatter and permanently deform upon shock, thereby providing limited capability to protect devices from normal shipping shocks in excess of 90 Gs. Because repeated shocks in excess of 90 Gs are representative of those knocks and drops often found in commercial shipping environments, the use of expanded polystyrene is inadequate to realistically protect the enclosed devices. Additionally, while expandable polystyrene is recyclable, it is not reusable, and as such represents an environmental concern.